Degradation and Fault Detection of Rotordynamic Machinery Using Real-Time Experimental Modal Analysis

本研究旨在为涡轮机械开发一种结合转子动力学、断裂力学和摩擦学的在线实时诊断能力，以预测设备何时应该停止使用。其概念是使用系统状态度量，来源于对运行响应数据的实验模态分析的应用。研究将从转子-轴系统的分析模型中获得数据，该系统具有中等大小的疲劳裂纹、轴承磨损、润滑剂变质和任何组合的饥饿。将从模型中导出与当前技术相匹配的转子动力系统的综合响应测量，并通过实验模态分析技术进行处理，以准确地指示系统的单个或多个故障及其临界状态。将确定实现操作系统在线诊断概念所需的信噪比。可行的概念将通过现场旋转动力学实验室进行初步实验验证。涡轮机械对我们社会的许多方面都很重要，特别是在发电、供水系统、航空和海军系统方面。避免灾难性故障目前主要是在计划的基础上进行的。开发一种技术来识别系统何时真正需要维护，从而避免不必要的停机，这将产生巨大的经济影响，因为它将减少执行昂贵检查程序的频率，并减少对过剩容量的需求。本研究的重点是存在裂纹的轴和迫在眉睫的轴承和润滑失效。它将使用当前技术进行响应测量，因此不需要对现有系统进行重大修改。进一步发展将使其成为一种联机诊断和预后工具，可与其他联机诊断技术并行使用。

This research study aims to develop an in-line real-time diagnostic capability for turbomachinery combining rotordynamics, fracture mechanics, and tribology to predict when equipment should be taken out of service. The concept is to use system condition metrics derived from the application of experimental modal analysis to operational response data. The research will begin with data derived from an analytical model of a rotor-shaft system having moderate sized fatigue cracks, bearing wear, and lubricant deterioration and starvation in any combination. Synthetic response measurements matching current technology for rotordynamic systems will be derived from the model, and processed by a technique for experimental modal analysis to accurately indicate the condition of the system single or multiple faults and their criticality. The signal-to-noise ratios required to implement concepts as in-line diagnostics for operational systems will be identified. Viable concepts will be subjected to a preliminary experimental validation using the onsite rotordynamics laboratory.Turbomachinery is important to many aspects of our society, especially for power generation, water supply systems, aviation and naval systems. Avoidance of catastrophic failure is presently performed primarily on a scheduled basis. Development of a technique that identifies when systems actually require maintenance, thereby avoiding unnecessary shutdowns, would have tremendous economic impact, because it would reduce the frequency with which expensive inspection procedures are performed, as well as lessen requirements for excess capacity. This study focuses on the presence of cracks in the shaft and impending bearing and lubrication failure. It would use current technology for response measurement, so it would not require major alterations to existing systems. Further development would make it implementable as an in-line diagnostic and prognostic tool, which could be employed in parallel with other in-line diagnostic techniques.